The change of season facillitates the need to temporarily obturate a ventillation duct to prevent or limit the escape of cooled or heated air introduced into a dwelling by its respective system.
To date, there is not one product on the market that will obturate the open end of a ventillation duct and provide both an airtight seal and highly insulative qualities.
Heretofore occupiers of dwellings with heating and cooling or ventillation systems would commonly use whatever is handy, i.e., rags, towels, blankets, plastic sheeting or protective covers. None of these methods provide the same level of sealing and insulative qualities along with ease of installation, removal, and protection from damage to the ventillation duct and its immediate surrounding area.